Other

Toru Yokota

Akira Fujinoki

Hiroyuki Nishimura

Akira Sato

Tetsuji Ueda

Yasuyuki Yaginuma

In the light of the disadvantages of the prior art technology, an object of the present invention is to provide a method for producing a synthetic quartz glass member for excimer lasers, which comprises, while suppressing the generation of reductive defects which impairs the resistance against laser radiations, incorporating a sufficient amount of hydrogen molecules capable of achieving a high resistance against laser radiation into the quartz glass, yet uniformly incorporating the hydrogen molecules to realize a flat distribution in refractive indices attributed to the distribution in the density of hydrogen molecules. It is also an object of the present invention to provide a synthetic quartz glass member for excimer lasers obtained by the production method above, which yields high resistance against laser radiations and homogeneity. The above problems have been overcome by a method for producing a synthetic quartz glass member for excimer lasers, which, in a method for producing a synthetic quartz glass member for excimer laser optics comprising a step of incorporating hydrogen molecules into a synthetic quartz glass body by heat treating the synthetic quartz glass body at a temperature of 600&deg; C. or lower under an atmosphere in a pressure range of 1 atm or higher but lower than 150 atm and containing hydrogen, said method comprises varying the pressure of the gas containing hydrogen either continuously or stepwise in at least a part of the heat treatment.

Method for producing synthetic quartz glass members for excimer lasers

An object of the present invention is to provide a synthetic quartz glass optical material having a high optical transmittance for a radiation 157 nm in wavelength emitted from F excimer laser and a high resistance against irradiation of a F excimer laser radiation, yet having a uniformity suitable for such a fine patterning using a F excimer laser, and to provide an optical member using the same. The problems above are solved by a synthetic quartz glass optical material for F excimer lasers having an OH group concentration of 0.5 ppm or lower, a fluorine concentration of 0.1 to 2 mol %, a hydrogen molecule concentration of 5&times;10 molecules/cm or lower, a difference between the maximum and minimum fluorine concentrations within 20 mol ppm, and a difference between the maximum and minimum refraction indices of 2&times;10 or lower.

Synthetic quartz glass optical material and optical member

A method for producing an optical quartz glass for use in excimer lasers, comprising a step of forming a porous silica preform by depositing silica in a soot-like form formed by flame hydrolysis of a high-purity volatile silicon compound, followed by a step of vitrifying said porous silica preform into transparent glass in an atmosphere containing water vapor and hydrogen, and a vertical type heating furnace for carrying out the production method therein.

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Koriyama, Japan

Toru Yokota